Thousands of schoolchildren are to be enrolled in a three-year study to find out if mobiles and wi-fi are damaging their brains.

The study, which has been commissioned by the Department of Health and is being carried out by Imperial College and the University of London, will monitor the cognitive development of 11 to 14-year-olds.

Youngsters will be asked to install an app on their phones which will capture the duration of calls, texts and internet use. Their brain function will be measured in Year 7 and again in Year 9.

"We need to investigate because it is a new technology," Professor Paul Elliot, director of Medical Research Council Centre for Environment and Health at Imperial College.

"Scientific evidence available to date is reassuring and shows no association between exposure to radiofrequency waves from mobile phone use and brain cancer in adults in the short term but the evidence available regarding long term heavy use and children's use is limited and less clear."

The Study of Cognition, Adolescents and Mobile Phones (SCAMP) is the largest study in the world to look at potential damage to children’s brains.

It will focus on cognitive functions such as memory and attention, which continue to develop into adolescence.

Cognition is how we think; how we make decisions; and how we process and recall information.

It is linked to intelligence and educational achievement and forms the building blocks of the innovative and creative potential of every individual and therefore society as a whole.

Seventy percent of 11-12 year olds in the UK now own a mobile phone, rising to 90 per cent by age 14.

Most research to date on mobile phones has focused on adults and risk of brain cancers.

While there is no convincing evidence that radio wave exposures from mobile phones effect health, scientists remain uncertain as to whether children's developing brains are more vulnerable.

It is feared that their developing nervous system may make them at greater risk of damage from the absorption of energy.

More than 160 secondary schools in the outer London area will today (TUES) receive invitations to take part.

Current UK health policy guidelines advise that children under 16 should be encouraged to use mobile phones for essential purposes only, where possible use a hands-free kit or text and, if calls are really necessary, to keep them short.

“As mobile phones are a new and widespread technology central to our lives, carrying out the SCAMP study is important in order to provide the evidence base with which to inform policy and through which parents and their children can make informed life choices,” said Dr Mireille Toledano of Imperial College, the Principal Investigator of the study.

Anyone who wants to find out more, or nominate their school to take part in SCAMP, can visit the website at www.scampstudy.org.